Tube polisher



Jan. 8, 1963 e. s. WING ETAL 3,071,903

TUBE POLISHER Filed De c. 27. 1960 2 Sheets-Sheet 1 A rramv'vs.

Jan. 8, 1963 e. s. WING ETAL 3,071,903

TUBE POLISHER Filed Dec. 27. 1960 2 Sheets-Sheet 2 F'la.3

INVENTOR. 66 04 66 s. (J/-6 ATTORNEYS.

3,071,903 TUBE POLISHER George S. Wing, Palos Verdes Estates, and Harry Louis Bochman, J12, Seal Beach, Calif., assignors to Hi-Shear Corporation, Torrance, .Calif., a corporation of tSalifornia Filed Dec. 27, 1960, Ser. No. 78,650 7 Claims. (Cl. 51241) This invention relates to a device for polishing the outside ends of tubes.

Heat exchanger tubes ordinarily are mounted by inserting their ends into end plates. When the end plates are removed to service the equipment, it is generally found that the first few inches of the outside ends of the heat exchanger tubes are corroded. In order to properly reassemble the equipment, it is necessary to polish off this corrosion. This has heretofore been a difficult and time-consuming task, due to the large number of tubes involved, the muscular exertion required, and the limited physical access. It is an object of this invention to provide a polishing device which can expeditiously carry out this polishing operation.

A device according to this invention is adapted to be operated by a motor which provides rotative force. The device includes a drive gear and a drive plate which are rotatable relative to each other, the motor supplying the power for this rotation. A spindle gear is journaled to the drive plate in driving connection with the drive gear, and a spindle is mounted on the drive plate so as to be driven by the spindle gear. Relative rotation of the drive plate and drive gear turns the spindle gear on its own axis, and also revolves this axis around the drive gears axis. Abrasive means are provided on the spindle, the result being that the abrasive means moves around the tube, polishing the same, with a surface speed greater than the speed of rotation of the spindle around the tools own axis.

A preferred but optional. feature of the invention resides in providing the polishing surface as an endless belt which is driven by the spindle and supported to form a loop by a support arm which can be angularly moved so that the belt is movable toward and away from the tube. This movement is accomplished by rotation-responsive means which, in the preferred embodiment, constitutes a closing arm which swings outwardly as a consequence of rotation of the tool, this closing arm being interconnected with the support arm for moving it radially inward and outward.

The above and other features of this invention will be fully understood from the following detailed description and the accompanying drawings in which:

FIG. 1 is a perspective view of the presently preferred embodiment of the invention;

FIG. 2 is a side elevation partly in cut-away crosssection of the device taken at line 2-2 of FIG. 3; and

FIG. 3 is a cross-section taken at line 33 of FIG. 2.

The general arrangement of the presently preferred embodiment of a tool 10 according to the invention is shown in FIG. 1. It is driven by a typical hand-held air motor 11. Such a motor ordinarily has a handle 12, and off-on switch button 13, a frame connection 14 (FIG. 2) and a drive shaft 15.

Again with reference to FIG. 1, the tool has a cover 16 which protects the user from the moving parts, and a States atet Patented Jan. 8, 1963 grip 17 by which the greater part of the tools weight can be supported.

The device has a central axis 18 which is coincident with the central axis of a tube whose outer surface is to be polished. A pilot assembly 19 is located on this axis, and is intended to make a close fit with the inside of the tube. The actual polishing is accomplished by a pair of abrasive means 20, 21 which in the preferred embodiment compriseendless belts which are mounted to the tool by'means to be described. It will be seen from FIG. 1 that the belts are symmetrically mounted to the device and will simultaneously polish opposite sides of the tubing. The device acts to run the belts around their supports as Well as to rotate the supports around the central axis of the tool, thereby polishing entire periphery of the tubing, and with a polishing surface whose linear speed is greater than its speed would be if it were merely rotated around the tube, Without also being driven on the supports. The tube will ordinarily be polished to about three'of four inches from its end. This is accomplished by putting the pilot in the end of the tube turning on the power and moving the tool along the tube to polish the same.

The device will now be described in greater detail with initial reference to FIG. 2 in which the cover, drive shaft and frame connection are all illustrated.

The frame connection has threadedly mounted thereto a drive gear 22 which is a spur gear with exterior external teeth 23. To the drive shaft there is attached a drive plate 24. It will be seen that the drive gear and drive plate are relatively rotatable by the motor. In the particular example shown, the drive gear is held stationary and the drive plate is turned, but it will be recognized that it is equally possible to counter-rotate the two of them or to rotate the drive gear instead of the drive plate. It is the relative rotation which is important, provided, of course, that such relative rotation causes the abrasive means to move around a stationary tube. A fixed drive gear and a rotatable drive plate is the most advantageous arrangement.

The drive plate has attached to it pilot assembly 19, which includes a base plate 25 mounted to the drive plate by hold-down bolts 26. A tube 27 is tack-welded to the base plate and has an insert 28 near its end to which is threaded a rotatable pilot 29. This pilot enters the tube to be polished. An example of a tube to be polished is indicated by tube 30 shown in dashed lines in FIG. 2 with the pilot inside it. While the principal use for this tool is in polishing tubing, it can also be used to polish rod, in which event the pilot could be deleted or a cup-shaped pilot able to receive a solid end could be provided instead. A hollow guide through the drive plate, and a hollow shaft motor forms another arrangement for rodpolishing, the guide acting as a pilot.

An intermediate gear 31 is journaled to the drive plate by means of a stud 32 which acts as a bearing for the gear. This intermediate gear is engaged with the drive gear and with a spindle gear 33. This spindle gear is journaled to the drive plate by means of a spindle 34 to which the gear is attached, the spindle being jourualed in the plate by a bearing 35.

It will now be seen that relative rotation between the drive gear and the drive plate will cause the gear train consisting of drive gear, intermediate gear, and spindle gear to rotate the spindle around its own spindle gear axis as well as to rotate the spindle gear axis around the central axis 36 of the drive plate, which is also the central axis of the tool. The central axes (of rotation) of all gears are parallel to axis 36. Thus the spindle is adapted to turn a pulley 37 which forms one end journal for the abrasive means, the pulley being mounted to spindle 34. A bearing 38 is provided for journaling the spindle at its outer end. This bearing is mounted in a support 39, that is threaded to the drive plate.

An abrasive belt 40 is wrapped around pulley 37 and around an idler pulley 41 (see FIGS. 2 and 3). This idler pulley is mounted on a support arm 4-2 which forms a portion of a swing arm assembly 43. At the end of support arm 42 there is a shaft 44 to which the idler pulley is mounted. The support arm is held to support 39 by a retaining ring 45, and includes a sleeve 46 which surrounds the support so that it is freely rotatable relative to the support. Rotation of the sleeve causes the support arm together with its idler pulley to move in an are around the spindle axis (with which sleeve 46 is concentric) so as to swing the abrasive belt toward and away from the central axis of the tool.

The swing arm assembly further includes an arm portion 47 which curves around the axis so as to pass the tube, and which has near its terminal end 48 a pin 49 which extends downwardly to fit into a slot 50 in a closing arm -1 which will be further described below. Arm 47 also has a stop 52 comprising a pin extending in the same direction as pin 49 which is intended to stand in the path of the closing arm to define an extreme position thereof. It will be seen that movement to the right or left of pin 49 in FIG. 3 will cause the swing arm assembly to turn counter-clockwise and clockwise, respectively, to move the abrasive means away from and toward the central axis respectively.

Further with respect to closing arm 51, this arm has a curved section 53 which goes around the central por tions so as not to interfere with the tube. It has a fly weight 54 at its free end. It is freely journaled to a support 55 corresponding to support 39. In the example given, the drawings have been simplified by showing in FIG. 2 only the complete assembly for one of the abrasive means. It will be recognized that these assemblies are duplicated, there being another set of intermediate gears and spindles and associated equipment. For example, in FIG. 2, there is shown a closing arm 56 which is loosely fitted around support 39 whose radial movements as a function of velocity of rotation will be effective to move abrasive means 21 toward and away from the axis. Closing arm 51 is freely fitted to support 55 in the same manner.

Closing arm 51 has slot 50 which extends radially from the central axis of the tool when the tool is not in operation. When the tool operates, the fiy weight will move outwardly, thus moving the slot and the pin which fits in it to the left in FIG. 3. This movement will continue until the closing arm strikes stop 52.

A coil spring 57 interconnects arm 47 of swing arm assembly 43 and a corresponding arm 58 of swing arm assembly 59 so as to bias the two assemblies, in the power-off condition, with their respective idler pulleys at their maximum distance from the central axis of the tool.

The operation of the device will now be described. Starting with the tool at rest with the abrasive means in the position shown in FIG. 3, the pilot is placed inside of the end of the tubing and the motor is turned on. This starts the epicyclic gear train in operation, rotating the spindles which gives a linear velocity to the abrasive belt around the respective pulleys and also rotates the drive plate to which the spindles are mounted. Thus the surface speed of the abrasive belts relative to the tube is greater than the velocity which would result merely from rotation of the spindle axes around the central axis. The tool is now slid back and forth along the end of the tube until it is suitably polished. During this time the belts are biased against the tube by virtue of the centrifugal force given to the fly weights which, with respect to FIG. 3, will cause fly weight 54 to move radially outward, that is to the left in FIG. 3. This would move arm 47 to the left and support arm 42 clockwise to bias the abrasive arm toward the tubing. The maximum movement is restricted by the closing arms striking stop 52. When the motor is turned off, the device will return to the condition shown in FIG. 3 by virtue of the pull exerted by the spring which tends to move swing arm assemblies count er-clockwise around their respective spindle axes to retract the abrasive belts from the tubing. There is, of course, no centrifugal force at this time tending to move the fiy weight radially outward.

This invention thereby provides a convenient means for polishing the ends of tubing of all classes but is particularly suitable for tubes or rods wherein the end few inches need to be polished, and in which access from the sides is relatively restricted.

This invention is not to be limited by the embodiment shown in the drawings and described in the description which is given by way of example and not of limitation, but only in accordance with the scope of the appended claims.

We claim:

1. A tube polisher comprising: a drive gear and a drive plate adapted to be relatively rotated; an intermediate gear and a spindle gear journaled to the drive plate; all of said gears and drive plate having parallel central axes of rotation, the intermediate gear being meshed with the spindle gear and the drive gear; a spindle connected to and driven by the spindle gear, whereby relative rotation of the drive gear and the drive plate turns the spindle on its own axis and also revolves its axis around the drive plate axis; a closing arm freely journaled to the drive plate and having a free weighted portion spaced from its journaled point adapted to swing outwardly from the central axis when rotated; a rotatable swing arm assembly journaled to the drive plate including an arm portion engaged to the closing arm, and a support arm adapted to be moved arcuately toward and away from the central axis of the drive plate when the closing arm is swung outwardly therefrom; abrasive means including a polishing surface parallel to said axes mounted to and driven by said spindle, said polishing surface also being mounted to said support arm whereby rotation of the swing arm assembly selectively moves the polishing surface toward and away from the central axis of the tool; and a pilot assembly mounted to said drive plate so disposed and arranged as to be able to enter a tube whose outer surface is to be polished by the polishing surface to hold the same in alignment therewith, whereby relative rotation of the drive gear and drive plate rotates the abrasive means around the outer surface of the tube, the polishing surface also being moved relative to the tube as a consequence of rotation of the spindle, whereby the entire periphery of the tube is polished by a polishing surface traveling at a linear speed relative to the tube surface greater than the speed of rotation of the polishing surface would be in the absence of spindle rotation.

2. A tube polisher according to claim 1 in which the polishing surface comprises an endless belt driven by two pulleys, a first of said pulleys being mounted to and driven by said spindle and a second of said pulleys being an idler journaled to the support arm.

3. A tube polisher according to claim 2 in which the closing arm has a slot therein and the swing arm assembly carries a pin engaged in the slot, rotation of the closing arm thereby rotating the swing arm assembly.

4. A tube polisher according to claim 3 in which springing means bias the closing arm to an inward position and thereby bias the polishing surface away from the central axis of the tool.

5. A tube polisher according to claim 4 in which the swing arm assembly carries a second pin, which is disposed in the path of the closing arm for limiting its maximum movement away from the central axis.

6. A tube polisher according to claim 5 in which a cover is provided which surrounds the drive plate and which carries a handle for supporting the assembly.

7. A tube polisher according to claim 1 in which the drive gear, intermediate gear, spindle gear, spindle, closing arm, abrasive means and swing arm assembly are provided in pairs symmetrically disposed relative to the central axis of the drive plate, whereby the polisher is balanced, and simultaneously polishes opposite sides of the tube.

References Cited in the file of this patent 6 UNITED STATES PATENTS 2,434,769 Jones Jan. 20, 1948 2,801,497 Moseley Aug. 6, 1957 FOREIGN PATENTS 10 137,689 Great Britain Jan. 22, 1920 255,664 Italy Oct. 31, 1927 

1. A TUBE POLISHER COMPRISING: A DRIVE GEAR AND A DRIVE PLATE ADAPTED TO BE RELATIVELY ROTATED; AN INTERMEDIATE GEAR AND A SPINDLE GEAR JOURNALED TO THE DRIVE PLATE; ALL OF SAID GEARS AND DRIVE PLATE HAVING PARALLEL CENTRAL AXES OF ROTATION, THE INTERMEDIATE GEAR BEING MESHED WITH THE SPINDLE GEAR AND THE DRIVE GEAR; A SPINDLE CONNECTED TO AND DRIVEN BY THE SPINDLE GEAR, WHEREBY RELATIVE ROTATION OF THE DRIVE GEAR AND THE DRIVE PLATE TURNS THE SPINDLE ON ITS OWN AXIS AND ALSO REVOLVES ITS AXIS AROUND THE DRIVE PLATE AXIS; A CLOSING ARM FREELY JOURNALED TO THE DRIVE PLATE AND HAVING A FREE WEIGHTED PORTION SPACED FROM ITS JOURNALED POINT ADAPTED TO SWING OUTWARDLY FROM THE CENTRAL AXIS WHEN ROTATED; A ROTATABLE SWING ARM ASSEMBLY JOURNALED TO THE DRIVE PLATE INCLUDING AN ARM PORTION ENGAGED TO THE CLOSING ARM, AND A SUPPORT ARM ADAPTED TO BE MOVED ARCUATELY TOWARD AND AWAY FROM THE CENTRAL AXIS OF THE DRIVE PLATE WHEN THE CLOSING ARM IS SWUNG OUTWARDLY THEREFROM; ABRASIVE MEANS INCLUDING A POLISHING SURFACE PARALLEL TO SAID AXES MOUNTED TO AND DRIVEN BY SAID SPINDLE, SAID POLISHING SURFACE ALSO BEING MOUNTED TO SAID SUPPORT ARM WHEREBY ROTATION OF THE SWING ARM ASSEMBLY SELECTIVELY MOVES THE POLISHING SURFACE TOWARD AND AWAY FROM THE CENTRAL AXIS OF THE TOOL; AND A PILOT ASSEMBLY MOUNTED TO SAID DRIVE PLATE SO DISPOSED AND ARRANGED AS TO BE ABLE TO ENTER A TUBE WHOSE OUTER SURFACE IS TO BE POLISHED BY THE POLISHING SURFACE TO HOLD THE SAME IN ALIGNMENT THEREWITH, WHEREBY RELATIVE ROTATION OF THE DRIVE GEAR AND DRIVE PLATE ROTATES THE ABRASIVE MEANS AROUND THE OUTER SURFACE OF THE TUBE, THE POLISHING SURFACE ALSO BEING MOVED RELATIVE TO THE TUBE AS A CONSEQUENCE OF ROTATION OF THE SPINDLE, WHEREBY THE ENTIRE PERIPHERY OF THE TUBE IS POLISHED BY A POLISHING SURFACE TRAVELING AT A LINEAR SPEED RELATIVE TO THE TUBE SURFACE GREATER THAN THE SPEED OF ROTATION OF THE POLISHING SURFACE WOULD BE IN THE ABSENCE OF SPINDLE ROTATION. 